Oil cooler

ABSTRACT

An oil cooler is disclosed. First and second plates are overlappedly joined together to form a plurality of tubes so as form a plurality of oil passages between the two plates. A plurality of the tubes are stacked to form cooling water passages. Embossing strips are repeatedly formed in skew along the length of first and second plates, and the embossing strips are crossed and joined. The embossing strips which are formed outside the tubes are also crossed and joined. Oil inlet/outlet holes are formed on both ends of the first and second plates respectively. Manifold parts of a certain area are formed around the oil inlet/outlet holes, and the embossing strips are preserved intact around the manifold parts. Accordingly, flow disturbances are sufficiently realized in the oil passages and in the cooling water passages owing to the embossing strips. Therefore, the heat exchanges are sufficiently improved between the oil and the cooling water, which flow through the radiator. Further, in the manifold parts, the area loaded with the oil pressure is reduced, thereby improving the oil pressure withstanding strength.

FIELD OF THE INVENTION

[0001] The present invention relates to an oil cooler, and more particularly, to an oil cooler in which embossing strips are provided to improve the heat exchange efficiency in the oil passages and the cooling water passages.

BACKGROUND OF THE INVENTION

[0002] The oil which is used in the automobiles and the like is heated during the operation due to the friction heat. As a result, the viscosity of the oil is lowered, and ultimately, the characteristics of the oil are lost, resulting in that the part subjected to the friction is worn out.

[0003] Accordingly, the oil temperature has to be maintained at a proper level, and for this purpose, an oil cooler is installed within the radiator which cools down the engine cooling water, so that the oil can be cooled with the cooling water flowing through the radiator.

[0004] An intra-radiator oil cooler disclosed in U.S. Pat. No. 5,369,883, as shown in FIG. 1, is constituted as follows.

[0005] An oil inlet 3 and an oil outlet 5 are disposed at the sides of the oil cooler 1 respectively. An oil passage 11 is formed such that two plates 7 and 9 are overlappedly brazed mutually. Cooling water passage 13 is braze-formed and separated from the oil passage part 11. The cooling water passage 13 is formed by the brazed embossing part 9 a of the plates 7 and 9.

[0006] Within the oil passage part 11 which is formed by brazing the plates 7 and 9 mutually overlappedly, there is inserted an internal fin 15 made of an aluminum thin sheet, so that the oil can be disturbed during its flow, thereby improving the heat exchange with the cooling water.

[0007] An oil cooler disclosed in Korean Utility Model Laid-open No.2000-0019797 and Korean Patent Application Laid-open No.2001-0046175, as shown in FIG. 2, comprises an oil inlet 19 for introducing the oil; an oil outlet 21 for discharging the oil; an oil passage 23 for the flow of the oil; and a cooling water passage 25 for the flow of the cooling water.

[0008] The oil passage 23 is constituted such that two press-formed plates 27 and 29 are overlappedly brazed together. An internal fin 31 made of an aluminum thin sheet is inserted into the oil passage 23 to disturb the oil flow, thereby improving the heat exchange with the cooling water.

[0009] In the cooling water passage part 25, there is also inserted an outer fin 33 made of a corrugated aluminum thin sheet. This oil cooler 17 is manufactured in such a manner that a close contact assembling is carried out first, and then a furnace brazing is carried out.

SUMMARY OF THE INVENTION

[0010] The present invention provides an oil cooler in which a separate outer fin is not inserted into the cooling water passages, and a separate internal fin for disturbing the oil flow is not inserted, but a sufficient heat exchange is realized between the oil and the cooling water, as well as improving the oil pressure withstanding characteristics.

[0011] In accordance with an embodiment of the present invention, first and second plates are joined together to form tubes of oil passages, and the tubes being stacked in a plurality to form cooling water passages between them. The first and second plates are embossed in a lateral direction in skew to form a plurality of embossing strips, and the embossing strips are continuously formed along the length of each of the first and second plates. The embossing strips are crossed and joined, and the adjacent embossing strips are also mutually crossed and joined. Oil inlet/outlet holes are formed in both ends of the first and second plates, manifold parts of a certain area are formed around the inlet/outlet holes, and the embossing strips are preserved around the manifold parts.

[0012] The projected outside face of each of the embossing strips is flat so that the joining can be rendered easy, and the joining can be made firm.

[0013] In a sectional view of the embossing strip, the horizontal distance L1 of the connection face between the flat horizontal faces is same as or larger than the length L2 of the horizontal face.

[0014] The connection face is inclined, and therefore, the cross sectional view of the embossing strip is trapezoidal.

[0015] The embossing strip is straight or bent at the centerlines of the first and second plates to form a “>” shape (i.e., a “V-shape”).

[0016] The first and second plates are joined together to form tubes, and a flange is formed along each of the edges of the plates. The flange is provided with a marking part so that the assembling direction can be recognized during the assembling.

[0017] The marking part preferably consists of a slot or a protuberance, or a carving may be carried out.

[0018] From the oil inlet/outlet holes of the both ends of the first and second plates to the lengthwise outer portion, there are formed other embossing protuberances. Therefore, the embossing protuberances can be joined to each other regardless of the assembling direction of the first and second plates.

[0019] An upper end plate is coupled to the uppermost tubes among the plurality of the tubes, so that the oil pressure can be withstood.

[0020] A pair of tubular connection devices which communicate to the oil inlet/outlet holes are fitted to the upper end plate. An end of the tubular connection device is made to undergo an expansion process before being brazed to the first plate which is a part of the tubes and the upper end plate.

[0021] A lower end plate is coupled to the bottom of the lowermost tube set so that the oil pressure can be withstood, while the plate of the lowermost tube set, to which the lower end plate is joined, is not provided with an oil inlet/outlet holes.

[0022] A bent protuberance is formed on the end of the upper end plate or the lower end plate, so that the assembling can be rendered easier.

[0023] The oil cooler is made of an aluminum-clad material, and the joining parts are joined by brazing them. Or the oil cooler is made of stainless steel and the joining parts can be joined by brazing by using a filler metal plate consisting of a copper sheet or nickel sheet

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above object and other advantages of the present invention will become more apparent by describing in detail the preferred embodiments of the present invention with reference to the attached drawings in which:

[0025]FIG. 1 illustrates an example of the conventional oil cooler;

[0026]FIG. 2 illustrates another example of the conventional oil cooler;

[0027]FIG. 3 is a perspective view of the oil cooler according to the present invention;

[0028]FIG. 4 is a sectional view of the joined state of the respective plates of the oil cooler according to the present invention;

[0029]FIG. 5 is an exploded perspective view of the oil cooler according to the present invention;

[0030]FIG. 6 is a plan view of the plate used in the oil cooler according to the present invention;

[0031]FIG. 7 is a sectional view taken along a line A-A′ of FIG. 6;

[0032]FIG. 8 is a plan view of brazing regions and oil passage regions, a pair of plates being assembled in the oil cooler according to the present invention;

[0033]FIG. 9 is a sectional view, with a tubular connection device being coupled to an oil inlet/outlet of an upper end plate in the oil cooler according to the present invention;

[0034]FIG. 10 is a plan view of another embodiment of the plate used in the oil cooler according to the present invention; and

[0035]FIG. 11 is a sectional view taken along a line B-B′ of FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0036] As shown in FIGS. 3 to 5, the oil cooler 35 according to the present invention comprises first and second plates 49 and 51 joined together to form tubes 42 of oil passages 41 (refer to FIG. 4). The tubes 42 are stacked in a plurality to form cooling water passages 43 between them.

[0037] An upper end plate 45 is coupled to the top of the uppermost tube set so as to sufficiently withstand against the oil pressure. Tubular connection devices 37 and 39 are fitted to the upper end plate 45 to communicate an oil inlet hole and oil outlet hole. A lower end plate 47 is coupled to the bottom of the lowermost tube set so as to sufficiently withstand against the oil pressure.

[0038] The first and second plates 49 and 51 consist of a sheet strip respectively, with both ends of each of them being rounded. The first and second plates 49 and 51 are embossed in a lateral direction in skew to form a plurality of embossing strips 53. The embossing strips 53 are repeatedly formed along the length of each of the first and second plates 49 and 51.

[0039] The embossing strips 53 of the first and second plates 49 and 51 are crossed and brazed to form brazing regions 53 c so as to form tubes 42, i.e., oil passages 41.

[0040] The adjacent embossing strips (adjacent to the joined couple of the first and second plates) are crossed and brazed together to form other brazing regions 53 d through which cooling water passages 43 are formed.

[0041] As shown in FIGS. 5 and 6, oil inlet hole 55 and oil outlet hole 59 are formed in both ends of the first and second plates 49 and 51. Some parts around the oil inlet hole 55 and oil outlet hole 59 are removed to form manifold parts 57 and 61, while the embossing strips are preserved intact around the manifold parts 57 and 61.

[0042] The first and second plates 49 and 51 are joined together to form tubes, and a flange 63 is formed along the edge of each of the first and second plates 49 and 51. The flange 63 is provided with a marking part 63 a so that the assembling direction can be recognized during the assembling.

[0043] The marking part 63 a preferably consists of a slot or a bent protuberance, or a carving may be carried out. The marking part 63 a is formed on one of the rounded parts of the plate.

[0044] The brazing face (bottom face) of the flange 63 lies on the same level as that of an embossing inner face 53 b of the plate viewed when it is formed into tubes. The brazing face of the manifold part (57 or 61) lies on the same level as that of an embossing outer face 53 a of the plate viewed when it is formed into tubes.

[0045] Further, a plate 51′ of the lowermost tube, which is closely joined to the lower end plate 47, is not provided with an oil inlet and outlet holes.

[0046] As shown in FIG. 7, an outer face 53 a and an inner face 53 b of each of the embossing strips 53 are of a flat horizontal face, so that the joining can be rendered easier, and the joining strength can be strengthened.

[0047] In a sectional view of the embossing strip 53, the horizontal distance L1 of the connection face 53 e between the upper and lower faces (flat faces) is same as or larger than the length L2 of the horizontal face.

[0048] The connection face 53 e is inclined, and therefore, the cross sectional view of the embossing strip is trapezoidal. The connection face 53 e can be a curved face. The embossing strip 53 is straight.

[0049] Both ends of the upper end plate 45 are respectively provided with holes 45 a and 45 b which respectively communicate to the oil inlet hole 55 and oil outlet hole 59. The tubular connection devices 37 and 39 are fitted into holes 45 a and 45 b of the upper end plate 45 and into the holes 55 and 59 of the first plate 49 respectively.

[0050] As shown in FIG. 9, the tubular connection parts 37 and 39 are provided with threads on their inner and outer circumferences respectively.

[0051] The parts 37 a and 39 a of the tubular connection parts 37 and 39, which are inserted into the holes 45 a and 45 b of the upper end plate 45 and into the holes 55 and 59 of the first plate 49 respectively, are made to undergo an expansion process, before being brazed to the upper end plate 45.

[0052] Bent protuberances 45 c and 47 c are formed on the ends of the upper end plate 45 or on ends of the lower end plate 47, so that the assembling can be rendered easier.

[0053] In this oil cooler, when the first and second plates 49 and 51 are overlappedly brazed together, the inside faces 53 b of the embossing strips 53 of the first and second plates 49 and 51 and the bottoms of the flanges 63 are braze-joined together.

[0054] As shown in FIG. 8, the embossing strips 53 are crossedly contacted to each other, and thus, the spaces other than the brazing regions 53 c form oil passages. Further, the flange 63 is formed all around, and therefore, any leakage of the oil can be prevented.

[0055] In FIG. 8, the solid lines indicate the embossing strips of the first plate 49, while the dotted lines which cross the solid lines indicate the embossing strips of the second plate.

[0056] Further, in the oil passages 41 which is formed by overlappedly coupling the first and second plates 49 and 51, the oil cannot flow straightly, but is forced to flow moving up and down and rightward and leftward as shown in FIG. 8. Thus the flow of the oil is disturbed, and therefore, the heat exchange efficiency is improved.

[0057] Further, if a plurality of the pairs of the plates, i.e., a plurality of the tube sets are stacked in the same direction, then the outside faces 53 a of the first and second plates 49 and 51 can be brazed together, resulting that the cooling water passages 43 are formed.

[0058] In these cooling water passages 43 like in the oil passages 41, the flow of the cooling water is disturbed up and down and rightward and leftward, and therefore, the efficiency of the heat exchange with the oil is improved.

[0059] Further, the embossing strips 53 are formed also around the manifold parts 57 and 61 of the first and second plates 49 and 51, and therefore, when the first and second plates 49 and 51 are overlappedly assembled to form the tubes 42, the areas of the manifold parts 57 and 61 subjected to the oil pressure are reduced, thereby improving the oil pressure withstanding strength.

[0060] The regions around the manifold parts 57 and 61 are not helpful to the heat exchange, but are vulnerable to the oil pressure. However, owing to the embossing strips formed around the manifold parts 57 and 61, the oil pressure withstanding characteristic is improved.

[0061] Further, the marking part 63 a is formed on only one face of each of the first and second plates 49 and 51. Therefore, when forming the tubes 42 by overlappedly coupling the upper and lower plates 49 and 51, and when forming the cooling water passages 43 by stacking a plurality of the tubes 42, the first and second plates 49 and 51 can be prevented from being assembled in an erroneous direction.

[0062] Further, the second plate 51 of the lowermost tube set is not provided with an oil inlet and an oil outlet, and therefore, the oil pressure withstanding strength is improved, while preserving the function of the oil passages, because the mentioned second plate 51 is braze-joined to the lower end plate 47.

[0063] The upper and lower end plates 45 and 47 are for improving the oil pressure withstanding strength.

[0064] The tubular connection parts 37 and 39 are firmly assembled to the upper end plate 45 through the tube expansion process as shown in FIG. 9, and therefore, the upper end plate 45 can also serve as a medium for braze-joining the tubular connection parts 37 and 39 to the first plate 49 of the uppermost tube set.

[0065] Further, a pair of protuberance parts 45 c and 47 c are provided on each of semicircular ends of the upper and lower end plates 45 and 47 in such a manner for the protuberance parts 45 c and 47 c to surround the uppermost plate and the lowermost plate.

[0066] The assembling is carried out in such a manner that the protuberance part 45 c should surround the uppermost first plate 49, and therefore, the holes 45 a and 45 b of the upper end plate 45 can be easily aligned to the oil i/o holes 55 and 59 of the first plate 49.

[0067]FIG. 8 is a plan view of the brazing regions 53 c and oil passage regions, when the first and second plates 49 and 51 are overlappedly assembled in the oil cooler according to the present invention.

[0068] The brazing regions 53 c are provided all along the flange 63 continuously. Therefore, the brazing regions 53 c of the first and second plates 49 and 51 can be assured to the maximum, and thus the withstanding strength against the oil pressure can be improved.

[0069] Further, since the brazing regions 53 c in the oil passages 41 are formed all along the flange 63, the first and second plates 49 and 51 are overlappedly assembled to form the tubes 42 for forming the oil passages 41.

[0070] A plurality of these tubes 42 are stacked in the same direction to form the cooling water passages 43. The contact points of the embossing strips 53, i.e., the brazing regions 53 d of the side of the cooling water passages 43 (refer to FIG. 4) are positioned where the cooling water starts to contact.

[0071] In this manner, if the tube sets are stacked up to some layers, the brazing layers 53 d of the embossing strips 53 to the side of the cooling water passages 43 are assured to the maximum area, thereby improving the oil pressure withstanding strength.

[0072] Further, in a sectional view of the embossing strip 53, the connection face which connects the horizontal faces 53 a and 53 b has a horizontal distance L1 same as or larger than the length L2. Accordingly, the brazing areas are reduced, while the heat exchange areas are increased, resulting in that the passage resistance is reduced, thereby improving the heat exchange efficiency.

[0073]FIG. 10 is a plan view of another embodiment of the first and second plates used in the oil cooler 35 according to the present invention.

[0074] Here, embossing strips 73 are bent along the centerlines of first and second plates 71 and 72 to form a “<” shape (i.e., a “V-shape”). The first and second plates 71 and 72 are provided with a flange 81 along their edges so that the plates can be coupled together to form tubes.

[0075] As shown in FIG. 11, protruded outer face 73 a and inner face 73 b of each of the embossing strips 73 are flat so that the joining can be easy and strong.

[0076] Further, in a sectional view of the embossing strip 73, the horizontal distance L1 of a connection face 73 e which connects the upper face (flat face) and the bottom face (flat face) is same as or larger than the length L2 of the flat face.

[0077] Thus the brazing areas are reduced, and the heat exchange areas are increased, resulting in that the heat exchange efficiency is improved. The connection faces 73 e are inclined, and therefore, the cross section is trapezoidal. The connection face 73 e can be made curved.

[0078] In the case where the embossing strips 73 are of a “<” shape, the first and second plates are coupled together with the first plate 71 is rotated by 180 degrees and with the second plate 72 not rotated, thereby forming the oil passages and the cooling water passages.

[0079] Surrounding each of oil inlet hole 83 and oil outlet hole 85 of the first and second plates 71 and 72, there are disposed a plurality of embossing protuberances 79, and therefore, the embossing protuberances 79 of the first and second plates 71 and 72 are joined to each other regardless of the joining direction of the first and second plates 71 and 72.

[0080] The embossing strips are removed around the oil inlet hole 83 and oil outlet hole 85 respectively to form manifold parts 75 and 77. The embossing strips are preserved around the manifold parts 75 and 77, and therefore, the oil pressure withstanding strength is improved at both ends of the plates. It is a matter of fact that “<” shaped embossing protuberances can be formed instead of the embossing protuberances 79.

[0081] Further, in forming the tubes, i.e., the oil passages by coupling the first and second plates 71 and 72, and in forming the cooling water passages by stacking a plurality of the tubes, the following features are provided.

[0082] That is, the assembling direction of the first and second plates can be easily confirmed by the following measures. That is, a slot 81 a is formed on one end of each of the first and second plates 71 and 72, while a protuberance 81 b is provided on the other end of each of the first and second plates. Further, a slot or a protuberance 81 c is formed at the middle between the slot 81 a and the protuberance 81 b.

[0083] Accordingly, if the first and second plates 71 and 72 are coupled together with the first plate 71 rotated by 180 degrees and with the second plate 72 not rotated, then the protuberance 81 b is mated to the slot 81 a, and therefore, the assembling direction of the plates can be confirmed.

[0084] A plurality of the oil passages are stacked by utilizing the slot or protuberance which is formed on only one side of the flange between the both ends of the plates. Under this condition, it can be confirmed that a pair of the oil passages are assembled in the same direction.

[0085] In the oil cooler 35 of the present invention as presented above with the different embodiments, the oil flows in through the tubular connection device 37 to enter into the respective manifold parts 57.

[0086] Then the oil is distributed from the manifold parts 57 to the respective oil passages 41 so as to move in the lengthwise direction of the tubes 42. Then the oil is collected into the manifold part 61 to be returned through the tubular connection device 39.

[0087] Under this condition, the cooling water within the radiator flows to the cooling water passages 43, so that the oil of the oil passages 41 and the cooling water of the cooling water passages 43 would be subjected to heat exchanges, thereby lowering the temperature of the oil.

[0088] The above described oil cooler 35 should be preferably manufactured by the continuous furnace process, and for this purpose, the components should be preferably made of aluminum. Particularly, the portions on which the brazing joining is carried out should be preferably made of an aluminum alloy on which a filler metal for brazing is clad.

[0089] Of course, first the components can be made of stainless steel or nickel steel, and then a thin copper sheet is adopted as the filler metal.

[0090] Further, besides the illustrated shapes, the plates can be formed in oval, rectangular, polygonal and the like. In any case of shape, the method of forming the oil passages and the cooling water passages is same as the above described embodiments.

[0091] Further, the above embodiments are for the oil cooler for the vehicle transmission, but if the plates are made round, they can be applied to the engine oil cooler.

[0092] According to the present invention as described above, the embossing strips are formed over the entire surface of the upper and lower plates, and therefore, the areas of the heat exchange are increased. Further, the flows of the oil and the cooling water are not straight, but are broken down up and down and leftward and rightward.

[0093] Thus sufficient disturbances are realized for the flows of the oil and the cooling water so as to improve the efficiency of the heat exchange. Further, the braze-joining regions are formed at regular intervals in the oil passages and the cooling water passages, and therefore, the oil pressure withstanding characteristics are improved.

[0094] Further, the conventional internal fin and the external fin, which are inserted into the oil passages and the cooling water passages for disturbing the flows of the oil and the cooling water, are eliminated. Consequently, the material cost and the processing cost are lowered, and the die cost and the facility cost are curtailed, so as to ultimately save the manufacturing cost of the oil cooler. 

What is claimed is:
 1. An oil cooler comprising: first and second plates joined together to form tubes of oil passages; the tubes being stacked in a plurality to form cooling water passages between them; the first and second plates being embossed in a lateral direction in skew to form a plurality of embossing strips, and the embossing strips being repeatedly formed along a length of each of the first and second plates; the embossing strips of the first and second plates being crossed and joined, and adjacent embossing strips (adjacent to the joined couple of the first and second plates) being also mutually crossed and joined; and oil inlet /outlet holes formed in both ends of the first and second plates, manifold parts of a certain area formed around the i/o holes, and the embossing strips being preserved around the manifold parts.
 2. The oil cooler as claimed in claim 1, wherein a projected outer faces of each of the embossing strips are flat to make it easy to join and to reinforce a joining strength.
 3. The oil cooler as claimed in claim 2, wherein in a sectional view of the embossing strip, a horizontal distance L1 of a connection face between a flat face and another flat face is same as or larger than a length of the flat face.
 4. The oil cooler as claimed in claim 1, wherein the connection face is inclined, and therefore, the embossing strip has a trapezoidal cross section.
 5. The oil cooler as claimed in claim 1, wherein the embossing strip is straight.
 6. The oil cooler as claimed in claim 1, wherein the embossing strips are bent at their middle to form a V-shape.
 7. The oil cooler as claimed in claim 1, wherein a flange is formed around an entire edge of each of the first and second plates so as to form tubes when the first and second plates are joined together.
 8. The oil cooler as claimed in claim 7, wherein the flange is provided with a marking part.
 9. The oil cooler as claimed in claim 8, wherein the marking part comprises a slot or a bent protuberance.
 10. The oil cooler as claimed in claim 1, wherein surrounding each of oil i/o holes of the first and second plates, there are disposed a plurality of embossing protuberances, and therefore, the embossing protuberances of the first and second plates are joined to each other at a same point regardless of a joining direction of the first and second plates.
 11. The oil cooler as claimed in claim 1, further comprising: an upper end plate coupled to an uppermost tube set, for increasing an oil pressure withstanding strength; a pair of tubular connection devices fitted to the upper end plate, for being communicated to the oil inlet/outlet holes; and an end of each of the tubular connection devices being fitted to the first plate through a tube expansion process before being brazed.
 12. The oil cooler as claimed in claim 1, further comprising: a lower end plate coupled to a bottom of a lowermost tube set, for increasing the oil pressure withstanding strength; and a plate of the lowermost tube set not having an oil i/o hole, and the plate being joined to the lower end plate.
 13. The oil cooler as claimed in claim 11, wherein bent protuberances are formed on both ends of the upper end plate or the lower end plate, so as to make it easy to assemble.
 14. The oil cooler as claimed in claim 1, wherein the oil cooler is made of an aluminum-clad material, and respective joining parts are braze-joined.
 15. The oil cooler as claimed in claim 1, wherein the oil cooler is made of stainless steel and the respective joining parts are made of a filler metal plate with a thin copper sheet or nickel sheet, and are braze-joined. 